Steam-engine indicator.



No. 63|,463. y Patented Aug. 22, |899.v4

W. H. HARRISON.

STEAM ENGINE INDICATOR.

(Application fxled Dec. 14, 1896.)

(No Modem ML@ i 5mm 'H mm,

UNITED STATES PATENT OFFICE.

VILLIAM H. HARRISON, OF BRAINTREE, MASSACHUSETTS.

STEAM-ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 631,463, dated August 22, 1899,

Application filed December 14, 1896I Serial No. 615,667. (No model.)

To ttl wwm t may concern:

Be it known that I, WILLIAM HENRY HAR- RISON, of Braintree, in the county of Norfolk and State of Massachusetts, have invented certain new and useful Improvements in Steam-Engine Indicators, of which the following, taken in connection with the accompanying drawings, is a speciiication.

My invention relates to that class of steamengine indicators in which the range of the piston movement made small to avoid false vibrations is multiplied by a lever combined with a parallel motion, causing the pencil to move up and down through a much greater distance and in an approximately straight line.

On the said accompanying drawings,Figure represents an elevation; Fig. 2, a plan, and Fig. 3 a vertical cross-section, taken through cylinder and spring in my improved indicator. Fig. 4: is a detached view from the same, showng the cross-head G G.

All the views are fullsize; but I do not limit yself to the dimensions or proportions there down or given in the description.

A A is the principal piece or base, having ille cylinder C O at the right-hand end and the paper drum O O and the grooved wheel and the small pulleys for the cord at the left hand.

I3 is a pipe by means of which steam or fluid pressure is brought into the cylinder O O above the piston E, forcing it down andcausing a tension upon the spring H. The pipe B is fitted with the usual cone-joint or union for connecting with an engine or pump and maybe formed on the base A A n the mannerand location shown in the drawings or different, if required.

The piston E has its rod F passing up through the bush and is threaded into the cross-head G G,vwhich is guided from turning by the slots Z Z and Z Z, and limited in its vertical motion to the height of said slots.

The cross-head G G is threaded into the nut K on the lowerend of spring H, which has an upper nut K threaded on the range-screw M.

Therange-screw M is supported in the hole at the upper end of'the spring-case I I and has a wing-head to facilitate turning.

The spring-case I I is of open form, as shown7 to preserve comparative coolness for the spring II and is supported :firmly on the base A A.

The cross-head G G has its end G' made long, so as to project through the front slot Z Z, and is provided with a small eye, in which are mounted a swivel and a knucklejoint connection with the link N, which carries the motion of the cross-head G G to the multiplying-lever L L, which has its vibrating fulcrum S mounted on the swing-arm T T, which swings horizontally on the base A A,With screw V for a pivot, having its center directly under the center of the eye at G on the cross-head G G. A

"W is an adjusting-screw pointing on stud X, Fig. 2, and is the means for a line adjustment of the pencil P.

The parallel motion for the pencil P on the long end of the lever L L, I have shown as obtained by the use of the radius-bar R, which is connected to the lever L L aud to the swingarm at T', the lengths of the parts being properly proportioned.

The drawings show the vibrating fulcrum S located between the ends of the lever L L and near to the link M. Consequently when the cross-head G G goes down by the action of the steam or `fluid upon the piston E the pencil P moves up and with an increased range of motion determined by the lever ratio.

The downwardly-acting piston E enables the hot water of condensation to leak freely around the piston E and pass quietly away from the lower end of cylinder O O through the large hole in the cap D.

If the piston E become clogged, the cap D is easy to remove, as well as the piston E, and the cylinder O O is easy to clean and this without dismounting the instrument or changing any of its adjustments. The spring H may also be tested by hanging suitable weights to the piston E or the cross-head G- G', the indicator being at the same time kept hot through the inlet B, which is attached to an engine.

The cross-head G G brings the lever L L clear of the spring H and enables me to readilyad just the range-screw M. 1

I call the screw M a range-screw, because by its use I can increase the range of comparatively weak springs and coarse scales up to twice the pressure they have been previously used for.

IOO

lVith indicators as previously constructed engineers are limited in their high-pressure diagrams to springs and scales ot' eighty or one hundred pounds per inch of height, and the diagram is unsatisfactory on account of its smallness. y

On the drawings, Fig. l shows the pencil P at the bottom ofthe drum O O and the crosshead G G at the top of its slot Z Z and the spring Il without strain. Consequently/if the drum is moved the line drawn on the paper will be the line of atmospheric pressure from which it is usual to measure the other lines and points. Turning the range-screw M in the proper direction, the spring H is carried bodily downward without strain and the atmospheric-pressure line will be carried up on the paper.

Comparing Fig. l with Fig. of the drawings, it will be noticed that the top nut K stands one-fourth of an inch higher on Fig. 3 than on Fig. l; but the cross-head G G stands at the top of the slots Z Z and Z Z in both figures. A tension has been put upon the spring ll, while the cross-head G G' and the pencil l remain at the same level as in Fig. l, and a base-line can be drawn on the diagram, the value of which may be calculated as follows: 'With the lever ratio six, as shown by the drawings, and the spring H, for instance, at fortythat is, one that gives a pencil movement of one inch Afor a range ol' pressure of forty pounds per square inch ot' steanr or ilnid-this base -line will represent sixty pounds per square-inch pressure above the atmosphere-that is, one-fourth multiplied by six multiplied by forty equals sixty. l have two and one-halt inches clear height on the paper, which, with the forty spring, gives me one hundred pounds range above the base-line, or together one hundred and sixty pounds above the atmosphere, and is ample height for taking diagrams from the highpressure cylinders of triple expansion engines when the pressure does not exceed one hundred and sixty pounds and does not fall below sixty pounds and using the forty spring and scale. lf the pitch of the range-screw M be, for example, tour-hundredths of an inch or one twenty-fifth, the extension of one-fourth inch on the spring H (shown in Fig. 3) is obtained by making six and one-fourth turns on screw M. The fractions of turns are easy to obtain on the graduated head I of the spring-case l l. The drawings, Figs. l and 2, show it divided intotwelve equal parts. One-twelfth of a turn on the range-screw yM will give the pencil P, if free, a motion up or down of two-hundredths of an inch, which will correspond to a change of pressure of one pound per square inch for a iifty spring and scale, eight-tenths of a pound for a forty, and six-tenths of a pound for a thirty. This ability to locate the base-line with reference to the atmospheric line is very useful when comparing the diagrams taken at the same time from the dilterent cylinders of multipleexpansion engines and multiple-cylinder compressors. '.lhedhigrams maybe taken, using equal springs and scales for all and losses ol' pressure between the cylinders noted by inspection of the actual diagrams.

In diagrams taken for use in power calculations or for setting valves there is no need to draw or use or determine the valve of the base-line. lVhen the indicator is connected, we can loosen or tighten the spring H by the range-screw -M until the cross-head G G has a free motion without touching either end of the slots Z Z and Z Z. The rate or scale for any spring will not be changed by the diilerent strains. There is another method by which this range-screw M may be used which will still be subject to this part of my invention, although I have not shown it in the drawings. lf the steam or iluid pressure is brought into the bottom of the cylinder C C and the order of the multiplying-lever L L changed, so that the pencil P will move coincident with the cross-head G G' and the spring ll made to work in compression by the upward motion of the piston E, the range-screw M can still be used and with the saine advantages as hereinbefore described.

l claim as my invention in a steam-engine indicatorl. The piston E and piston-rod F in the cylinder C C, in combination with the cross-head G G, the spring Il, and the pencil-moving mechanism consisting of the link N the vibrating fulcrum S the lever L L the radiusbar `t and the swing-arm T T, having the pivot-screw V concentric with the eye at G on the cross-head G G'.

The piston E and piston-rod F in the cylinder C C, in combination with the cross-head G G, the spring ll, the pencil-moving meehanism consisting of the link N the vibrating ulcrum S the lever L L the radius-bar R the swing-arm T T', having the pivot-screw Y concentric with the eye at G' on the crosshead G G, and the drum O O for paper.

3. The piston E and piston-rod F in the cylinder C C, in combination with the cross-head G G,the spring ll, the pencil-moving meehanism consisting of the link il the vibrating fulcrum S the lever L L the radius-bar R and the swing-arm T T', having the pivot-screw V concentric with the swivel at G on the cross-head G G, the drum O O for paper, and the range-screw M.

it. The piston E and the piston-rod F in the cylinder C C having at its closed top an inlet B above said piston E for the working llnid and at the bottom a free passage to the atmosphere.

5. The piston E and piston-rod F in the cylinder C C having at its closed top an inlet B above said piston E for the working fluid and at the bottom a free passage to the atmosphere in combination with the cross-head G G the spring lll and the pencil-moving mechanism consisting of the link N the vibrating fulcrum S the lever L L the radius-bar R and IOO IIO

two subscribing Witnesses, on this 16th day of November, A. D. 1896.

'l WILLIAM H. HARRISON.

Witnesses:

`TI-IoMAs P. HARRISON,

RICHARD C. HARRISON.

the swing-arm T T', having the pi\fot-seIeW V eoneentn'ie with the eye nl; G' ou the erosshead G GH.

A11 substantially as shown and described 5 and for the purposes hereiubefore set forth.

In testimony whereof I have signed my name to this speeeaton, in the presence of Corrections in Letters Patent No. 631,463.

It is hereby eertied that in Letters Patent No. 631,468, granted August 22, 1699, upon the application of VVilliaIn H. Harrison, of Braintree, Massachusetts, for an 'improvelnent in Stea1nEngine Indicators, errors appear in the printed specification requiring correction, as follows: On page 2, line 30, the Word at should read a, and same page, line 75, the Word valve should read value; and that the said Letters Patent should be read With these corrections therein that' the same may conform to the record of the ease in the .Patent Oiee.

Signed, countersigned, and sealed this 29th day of August, A. D., 1899.

[SEAL] WEBsTEn nnvis,

Assistant Seeietcwy of the Interon Countersgned A. P. GREELEY,

Acting Commissioner of Patents.

Corrections in Letters Patent No. 631,463.

Itis hereby certified that in Letters Patent No. 631,463, granted August 22, 1%99, upon the application of William H. Harrison, of Braintree, Massachusetts, for an .irnprovement in Steam-Engine Indicators, errors appear in the printed specification requiring correction, as follows: On page 2, line 30, the Word at should read a, and same page, line 75, the Word Valve should read value; and that the said Letters Patent should be read with these corrections therein that' the same may conform to the record of the case in the Patent Ofce.

Signed, countersigned, and sealed this 29th da)7 of August, A. D., 1899.

[sEAL] WEBSTER DAVIS,

Assistant Secretary of the Interior. Countersigned A. P. GREELEY,

Acting Commissioner of Patents. 

